Control of pneumatic selenoid

[kj3d]

I am using two solenoids, one is simply configured as a switch (on / off) Its function is simple, it switches air flow onto a brake, when air is on the brake is off. If its off the brake stops a ball screw rotating. Ideally I would like to switch air on before the command is sent to move the ball screw, but if power fails the ball screw brake to apply.

The second is a PWM controlled flow valve that will replace a conventional cooling fan.

My question is how is it best to configure these on an 6HC motherboard - ideally out7 and out8 would be good. Or alternatively please suggest what is best? With regards the simple on off solenoid the unit has a LED across the supply, do I need an additional flyback diode?

[kb58]

@kj3d Well first off, what voltage do the solenoids run on, and what current do they draw. Flyback diodes are always a good thing, but they may be there already.

[kj3d]

@kb58

Both the solenoid and flow valve are 24v - the board
jumpers are configured to supply 24v. Approx. 100ma each at 24v

[dc42]

@kj3d the MB6HC has flyback diodes built-in to all OUT ports except OUT0. So you don't need to add an external one.

[kj3d]

@dc42

Thanks - thats good to know. problem resolved and board working very well!!